Home sales between $10 and $49 million shot up, too, averaging 60 sales per quarter in the U.S. last year. A chunk of these properties sold in New York City. Here is what UrbanTurf’s old friend Jonathan Miller had to say about who is buying these homes and why:

“It’s a fairly even divide of U.S. and foreign buyers,” says Miller. “We now have this tall tower phenomenon.” A new market has essentially been created with these residential skyscrapers like 520 Park Avenue in New York City, he adds. “I refer to them as the most expensive safe-deposit boxes in the world.”